feat: limit-req support nodelay

apisix/plugins/limit-req.lua

@@ -36,6 +36,9 @@ local schema = {
         rejected_code = {
             type = "integer", minimum = 200, maximum = 599, default = 503
         },
+        nodelay = {
+            type = "boolean", default = false
+        },
     },
     required = {"rate", "burst", "key"}
 }
@@ -96,7 +99,7 @@ function _M.access(conf, ctx)
         return 500
     end
 
-    if delay >= 0.001 then
+    if delay >= 0.001 and not conf.nodelay then
         sleep(delay)
     end
 end

docs/en/latest/plugins/limit-req.md

@@ -42,6 +42,7 @@ limit request rate using the "leaky bucket" method.
 | burst         | integer | required    |         | burst >= 0                                                               | the number of excessive requests per second allowed to be delayed. Requests exceeding this hard limit will get rejected immediately.                                      |
 | key           | string  | required    |         | ["remote_addr", "server_addr", "http_x_real_ip", "http_x_forwarded_for", "consumer_name"] | the user specified key to limit the rate, now accept those as key: "remote_addr"(client's IP), "server_addr"(server's IP), "X-Forwarded-For/X-Real-IP" in request header, "consumer_name"(consumer's username). |
 | rejected_code | integer | optional    | 503     | [200,...,599]                                                            | The HTTP status code returned when the request exceeds the threshold is rejected.                                                                      |
+| nodelay       | boolean | optional    | false   |                                                                          | If nodelay flag is true, bursted requests will not get delayed  |
 
 **Key can be customized by the user, only need to modify a line of code of the plug-in to complete.  It is a security consideration that is not open in the plugin.**
 

docs/zh/latest/plugins/limit-req.md

@@ -42,6 +42,7 @@ title: limit-req
 | burst         | integer | 必须   |        | burst >= 0                                                              | t请求速率超过 （`rate` + `brust`）的请求会被直接拒绝。                                                                                            |
 | key           | string  | 必须   |        | ["remote_addr", "server_addr", "http_x_real_ip", "http_x_forwarded_for", "consumer_name"] | 用来做请求计数的依据，当前接受的 key 有："remote_addr"(客户端IP地址), "server_addr"(服务端 IP 地址), 请求头中的"X-Forwarded-For" 或 "X-Real-IP"，"consumer_name"(consumer 的 username)。 |
 | rejected_code | integer | 可选   | 503    | [200,...,599]                                                              | 当请求超过阈值被拒绝时，返回的 HTTP 状态码。                                                                                                        |
+| nodelay       | boolean | 可选   | false  |                                                                         | 如果 nodelay 为 true， 请求速率超过 `rate` 但没有超过 （`rate` + `brust`）的请求不会加上延迟, 如果是 false，则会加上延迟。 |
 
 **key 是可以被用户自定义的，只需要修改插件的一行代码即可完成。并没有在插件中放开是处于安全的考虑。**
 

t/plugin/limit-req2.t

@@ -0,0 +1,121 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+use t::APISIX 'no_plan';
+
+log_level('info');
+repeat_each(1);
+no_long_string();
+no_shuffle();
+no_root_location();
+
+run_tests;
+
+__DATA__
+
+=== TEST 1: add plugin for delay test
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1',
+                 ngx.HTTP_PUT,
+                 [[{
+                    "plugins": {
+                        "limit-req": {
+                            "rate": 0.1,
+                            "burst": 4,
+                            "rejected_code": 503,
+                            "key": "remote_addr"
+                        }
+                    },
+                        "upstream": {
+                            "nodes": {
+                                "127.0.0.1:1980": 1
+                            },
+                            "type": "roundrobin"
+                        },
+                        "desc": "upstream_node",
+                        "uri": "/hello*"
+                }]]
+                )
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 2: the second request will timeout because of delay,  error code will be ''
+--- abort
+--- timeout: 500ms
+--- pipelined_requests eval
+["GET /hello", "GET /hello"]
+--- error_code eval
+[200, '']
+
+
+
+=== TEST 3: add nodelay flag
+--- config
+    location /t {
+        content_by_lua_block {
+            local t = require("lib.test_admin").test
+            local code, body = t('/apisix/admin/routes/1/plugins',
+                ngx.HTTP_PATCH,
+                [[{
+                        "limit-req": {
+                            "rate": 0.1,
+                            "burst": 4,
+                            "rejected_code": 503,
+                            "key": "remote_addr",
+                            "nodelay": true
+                        }
+                 }]]
+            )
+
+
+            if code >= 300 then
+                ngx.status = code
+            end
+            ngx.say(body)
+        }
+    }
+--- request
+GET /t
+--- response_body
+passed
+--- no_error_log
+[error]
+
+
+
+=== TEST 4: the second request will not timeout because of nodelay
+--- abort
+--- timeout: 500ms
+--- pipelined_requests eval
+["GET /hello", "GET /hello"]
+--- error_code eval
+[200, 200]